Steering systems currently used include means for assisting the manual pumping means and are generally composed of manual control means, such as a steering wheel or the like, which operate the pumping means in order to move a steering actuator. Steering assist means are generally based on automatically operated pumping mechanical means, which are hydraulically connected to manual pumping means and which are operated by using measurements of the conditions of the pressurized fluid. Generally, automatic pumping means are based only on the operation of the manual control means, for example, the assist means pump an amount of fluid proportional to steering wheel rotation, without considering navigation conditions, such as for example cruising speed or the number of revolutions of the propulsion engine.
Moreover, assist means are generally operated automatically. At present there are no servo-assisted steering devices that can be operated both automatically and manually and that contemporaneously adjust or set the amount of fluid to be pumped into the assist hydraulic circuit.
Therefore, there is an unsatisfied need for a servo-assisted steering device which, by means of relatively simple and inexpensive arrangements, facilitates maneuvers during use of the vehicle to which the device is associated. A solution to that need involves the use of steering assist means, which can be adjusted both manually and automatically during operation, based, among other things, on the navigation conditions of the vehicle to which the device is associated.